An application of the invention is directed in general to the field of wireless communication systems. One of possible applications is the third generation mobile communications standard 3 GPP, and particularly in the release 5 and beyond wherein a high data rate service called High Speed Downlink Packet Access or HSDPA is defined.
A HSPDA service is made possible by use of a new shared channel called High Speed Downlink Shared Channel or HS-DSCH, mapped to several physical channels in the physical layer. A set of physical shared channels, presently up to 4, namely High Speed Shared Control Channels or HS-SCCH, is used to transmit all necessary control information for correct decoding and demodulating of HS-DSCH.
Only one HS-SCCH can be allocated to a user during a determined duration. However since several users might share the same HS-SCCH set and physical channels therein, the same HS-SCCH can be allocated to another user after the determined duration. The HS-SCCH is thus a discontinuously transmitted shared channel. The user equipment doesn't know which control channel is meant for it.